This invention relates to a document searching method for changing over between plural document databases, and constructing relationships between plural document databases.
As more and more document information is converted to electronic format, a greater need is emerging to search different types of document database simultaneously. For instance, users often wish to look up dictionaries relating to newspaper articles which they may find of interest.
In the past, it was possible to perform a search independently by changing over between plural document databases, but there was no way of examining the relevancy of sets of documents in other databases to a set of documents in one particular database.
If however the search is limited to the same document database, it is possible to search other document sets within that database. In this case, sufficient search speed is often obtained by calculating the relevance between documents before searching. Even with different databases, it is possible to search plural document databases at the same time if such a calculation is performed beforehand, but since the need for calculation increases as the number of databases increases due to increasing numbers of combinations, this method is not realistic.
It is also possible to first analyze the set of key documents on the user side to compose a search input, and then search in other document databases by using the input, but in this case, the user side has to receive all the information about the set of key documents, and if the document databases are on a network, the amount of traffic would be huge.
It is therefore an object of this invention to resolve the problems inherent in existing technology by allowing a user to specify an arbitrary set of documents in an arbitrary document database, and to efficiently search sets of documents relating to this set of documents from within any particular database.
When there is a large search input as in the case of a set of key documents, instead of using all the information in the search input, it is faster to perform a search using only topic words of the search input as a summary, and this also reduces the load on the network. In the context of this specification, xe2x80x9csummaryxe2x80x9d means a xe2x80x9cset of topic words for a set of documentsxe2x80x9d.
The document databases are located on servers on a network comprising a module for building a summary by selecting topic words for a set of documents within the document database, and a module for performing a search on any arbitrary summary.
A user who performs a search specifies a set of documents via a client to a server in which an source document database is stored, and receives a summary.
Next, the summary is sent to a server where a target document database to be searched is located, and a search result is received.
As the search interface of the client, a display area for a set of documents is first provided wherein the required set of key documents can be specified, and the database to be searched can also be selected. In the client, the user then selects an interesting set of documents from among a set of documents displayed in this display area, and if necessary, changes over the document database which is to be searched.
These and other objects, features and advantages of the present invention will become more apparent in view of the following detailed description of the preferred embodiments in conjunction with the accompanying drawings.